Afterthoughts
uncertainty in science | uncertainty in life | postscript | home
I have attempted to
give a simple account of my work together with a few personal background
details. None of the work was secret and it was published in about 140 papers
and three small books. Publication was a necessary part of the work, but I
never found writing easy and I rejected a number of invitations to write a
full-length book on the measurement of time. Since retiring I have often felt
like sending letters to the press, only to realise that by the time I had
decided what to say and how to say it, the topical interest would have gone.
The work I have described gave me great job satisfaction, to use the modern
jargon, reasonable financial reward, and wide recognition. Awards received were
several premiums from the IEE, the Charles Vernon Boys prize of the Physical Society,
The Tompion gold medal, the Popov gold medal and Wolfe award, the Rabi award,
an FRS and OBE.
It is with some diffidence that I now add a
few comments on matters that have been occupying my mind. Do we become wiser
with age? We certainly become more forgetful and less able to understand new
ideas, including the wonderful advances in the physical sciences. And yet in
some ways I feel wiser. Given the opportunity again I would make a conscious
effort to improve my personal relationships, being more helpful and tolerant to
my junior colleagues and more respectful to my seniors. In spite of spending
most of my time with academic and professional people I have never felt quite
on par with them, being unable to break completely with my working class or,
perhaps more accurately, my artisan class background. My directors were always
fair and helpful, introducing me to the leading figures in the scientific
establishment. It was my own limitations that inhibited me from starting interesting
discussions with them. It was possibly this difficulty of communication, and
the fact that I insisted in my opposition to the relativity theory as exposed
by Einstein, that stopped me from receiving quite the recognition that I
thought my experimental work deserved.
Uncertainty in science
My involvement
with measurement has made me increasingly aware of the complexity and
uncertainties of science and of human endeavour. Even in science nothing is
certain. Facts can be established only within the accuracy of the measurements
and experimental results should always be accompanied by the limits of error.
The most precise of all measurements is that of an interval of time, for which
the limit of error is less than 1 part in a million million. For many other
measurements, particularly in the physical sciences, the limits are very small,
but in others such as medicine they may be large and difficult to estimate. In
some sciences such as archaeology and cosmology wide deductions are made from
very dubious results and the findings should be treated with caution. The
so-called science of astrology is of course pure speculation and it is
unfortunate that the bogus and speculative sciences are given the most
attention on the media.
When the first
atomic clock was made at the NPL, visiting scientists asked how I knew that it
was constant. All I could say was that similar clocks made throughout the world
agreed within the limits claimed, and they enabled the unit of time to be
determined and used with a precision thousands of times better than the
astronomical second. We had to assume it was constant until it could be shown
to vary by reference to a more accurate standard. This is the position with all
the standards of measurements, but my listeners did not appear to be satisfied.
They believed in a perfect deterministic world.
There may be a
further limit to the accuracy of scientific results resting in the foundations
of the scientific structure. It was an important step forward when it was
realised that the basic units should be those of mass, length and time defined
in such a way as to be independent of one another, but it was not realised that
this is difficult and perhaps impossible, since all measurements are made in
the earth environment with its electric, magnetic and gravitational fields, the
effects of which are not easily disentangled. This limitation is usually
overlooked but should be considered when puzzling results are obtained.
The realisation
that scientific results cannot be established with certainty, prompted the
question of how science can claim to be any better than other branches of human
endeavour such as philosophy and religion. Indeed I think there are
similarities. It is a matter of probabilities and of what, as rational beings,
we can accept as true. Some scientific results are established with such small
limits of error that for all practical purposes they can be regarded as true;
but others are far more speculative.
Uncertainty in life
If we regard
religion with the same criteria, we can conclude that the founders of religions
observed certain modes of conduct, such as contemplation, truthfulness,
unselfishness and compassion led to a sense of peace and satisfaction. The same
conclusions can be drawn continuously from our own observations and can be
accepted as true. On the other hand there is no evidence to support the myths
that have been built into formal religions. In the whole of history there has
not been a single substantiated case of a virgin birth which must be regarded
as allegorical, although it constitutes a cornerstone of the Christian faith.
Such myths have been the cause of persecution and torture; although they have
also been the inspiration of great works of art. A firmly held faith helps
individuals to face life’s difficulties but, tragically, nearly all formal
religions instruct the faithful to oppose and destroy all those holding a
different faith. Religious intolerance has been the cause of many major wars
and is at the root of much of the strife throughout the world today. It might
have seemed sensible for the founders of the USSR to ban the teaching and
practice of religion and I remember seeing in a Leningrad museum what in my
view was an objective account of the religions of the world; but religion
refused to die. It seems that mysticism has a greater appeal than rationality.
Man needs a father figure to worship and a strict code of conduct to follow.
In my own time
there was hope that a more rational society might be built on the lines
advocated by writers like Wells and Bernal. Science was to be used for the good
of humanity and the economy was to be managed by experts. International
co-operation was to be secured through the United Nations, statesmen made
splendid declarations about human rights which have served as an inspiration to
individuals but have been ignored by states. Some of the ideas were implemented
in the UK with the welfare state and the NHS which relieved millions of our
poorer citizens from anxiety. The nationalised industries worked well with good
co-operation between workers and management. The services, the post office, the
gas, electrical and water authorities were helpful to the consumers and proud
of their efficiency. The civil service was highly motivated and free from
political bias. The capitalist system with adequate controls was working well.
But this was all changed with a new government which believed in unfettered
capitalist competition freed from the civilising restraints which had been
imposed by all previous governments. This has happened at a time when it has at
last been realised by all thinking people that severe restraints must be
imposed if the environment is to be maintained in a condition that will support
human life. The preservation of the environment is a huge task and it is to be
hoped that mankind will reverse the present headlong rush to destruction.
Louis Essen
July 1996
